What options were open to Harry Truman?

All his other choices were worse. That is to say, he had none. The Japanese were massing in southern Japan where they expected an invasion by Allied forces.

Not just the hard call with the A-bombs, but many others make Harry Truman the best President the U.S. ever had. I say that as a life-long Republican.

The only way the people of Japan, victims of the Emperor's and Japanese miltary's internal propaganda, would have surrendered was after the invasion of the island of Japan itself. This would have cost easily 100s of thousands more casualties for each side and been a very extended campaign. To avoid this, the atomic devices were dropped showing Japan that the Allies could inflict severe damage to the Japanese forces without Allied forces suffering comparable losses of property and persons.

The fact that diplomacy had already failed [remember Japan attacked Pearl Harbour even with the US requesting meetings with the Japanese Ambassador who was instructed to postpone the meeting until after and then inform the US there would be no further diplomatic relations] and the staggering amounts of potential casualties left Truman with little else to do in order to bring about an end to the conflict.

1) Use the atomic bombs to force Japan to surrender.

2) Invade. An invasion might be extremely bloody, as experienced at Tarawa, Saipan, Iwo Jima, and Okinawa. Those experiences led to military leaders to urge President Truman to use atomic weapons on Japan.

3) Blockade Japan. The US and allied navies would blockade Japan until they surrendered. Many historians claim the Japan was nearly ready to give up, but there is doubt that the Japanese military would have quit so readily. In any case, a blockade would have taken a long period of time and would have included naval and aerial bombardment that would still kill thousands of Japanese.

If I was Truman, it would know that it would be necessary to end the conflict and take out Japan (plus I would probably still feel the need for revenge after Pearl Harbour). However, I would not drop the bomb on Hiroshima (and certainly not on Nagasaki). In stead, if I were Truman, I would give Japan a warning first, and if they did not agree to drop out of the war, I would drop the bomb in the ocean far off the coast of Japan. While people would probably still be harmed by the force of the atomic bomb, at least I had provided a fair warning to Japan about what I was capable of doing, while at the same time I tried by best to minimize the risk of killing millions or innocent Japanese civilians.

Not too sure that he had any other workable solutions. An amphibious invasion of the Japanese home islands would have been, perhaps, too much of a financial burden as well as the tremendous cost in lives on both sides. Did we even have the capital to fund a prolonged ground war in Japan? There's also the possibility that the Soviets would have been able to land, on Hokkaido at least, and while it would have made taking the islands easier, we might have been looking at a divided Japan set up along the lines of Germany and Korea.

There was no other option that was as expedient and decisive. Operation Olympic (the invasion of the core islands) would have cost twice the manpower as Overlord. Especially after the failure of Market Garden, the bombs were gifts from god. We were losing 1,000 to 5,000 soldiers a day in the pacific, any delay what so ever would have been foolish and tragic.

He could have invaded the mainland where the fighting would have been house to house and suicidal. The emperor was a god figure in their culture, to die in his defense and that of japan would have been a great honor. We would have spent years taking the mainland and lost (according to estimates) up to a half a million troops. Our other option was to drop the bomb. We dropped leaflets at the ground zero sites telling people to evacuate in hopes of minimizing civillian casualties and then we flattened Hiroshima and Nagasaki. This ended the war much faster and with far fewer casualties.

he had the option of a full out invasion of Japan's mainland and seeing how they defended many non-important islands to the final man. the loss of life on both side would have been un acceptable.

the losses would have been in the millions. so dropping the bombs took hundreds of thoudands of lifes not dropping would have cost millions.

I wouldnt have wanted to be him to leave a legacy of being the 1st and only person to order the use of atomic bomb.

Enter into secret negotiations with the Japanese, allow them to overrun China, in return for a promise to pull out of various strategic island areas of the Pacific.

In this way, Chinese communism would have been nipped in the bud. Their military forces would have been exterminated. Chiang Kai-shek's military forces would have been exterminated as well.

Asia would effectively be divided into two spheres of influence: the USA and Japan.

Other options were an all out invasion or a military blockade of food and supplies to Japan.